Kiln



Oct. 16, 1945. H. M. BEATTY KILN 5 Sheets-Sheet 1 2 4 9 l 4 n n J d e li F llll lllll llll rlllll I INVENTOR. HE/WYM BEAM-r fld 770% 57%Arno/ave r25 Oct. 16, 1945. H. M. BEATTY KILN Filed July 4, 1942 5Sheets-Sheet 2 INVENTOR.

(HE/YPYM Benn-r 7 Oct. 16, 1945. H. M. BEATTY KIIJN 5. SheetsSheet 3Filed July 4, 1942 4L M F KILN Filed July 4, 1942 5 Sheets-Sheet 4 4 u mA s T on Y m & s N N 1 v M r P W m 3H 0 K 5 Sheets-Sheet 5 Ildl H. M.BEATTY KILN Filed Jul Oct. 16, 1945.

mmvron HENRY M BEA 77 Y BY $42 Arraeusrs Patented Oct. 16, 1945 UNITEDSTATES PATENT OFFICE KILN Henry M. Beatty, Shaker Heights, Ohio,assignor to The Kelley Island Lime and Transport Company, Cleveland,Ohio, a eorporauon of one Application Jilly 4, 1942, Serial No. 449,769r 20 Claims.

This invention relates to tunnel kilns of the continuous type forburning or calcining bulk limestone or various other materials andproducts, and more particularly to a kiln of this type em= bodyingimprovements which render the same more satisfactory and efiicient thansimilar kilns heretofore employed.

An object of my invention is to provide an improved kiln of this type inwhich gaseous mediumfor heating (or cooling) is made to pass through orpermeate the bulk material being treated.

Another object of the invention is to provide an improved constructionfor a kiln of this type in which the heated gases, after passing throughthe bulk material in the burning zone of the kiln, are used to preheatthe bulk material at a point in advance of the burning zone.

A further object of my invention is to provide an improved kiln in whicha car adapted to carry a load of bulk material is constructed withpassages or' openings for admitting or directing heat-' ing (or cooling)gaseous medium through the bulk material and in which sealing means isarranged to confine the gaseous medium to cause the same to pass throughthe material.

Still another object of this invention is to provide an improvedconstruction for a kiln car adapted to carry material to be treated andin which the body or load-carrying portion of the car has passages oropenings therein enabling the heated gases to pass through the material.

The invention also provides an improved tunnel kiln through which carsare pushed, while in an for the cars for substantially maintaining suchabutting relation.

The invention may be further briefly summari'zed as consisting incertain novel combinations and arrangements of parts hereinafterdescribed and particularly set out in the appended claims.

In the accompanying sheets of drawings,

Fig; 1 is a planview of a tunnel kiln embodying my invention;

Fig. 2 is a side view thereof;

Fig. 3 is a transverse sectional View, on a larger Scale, taken throughthe kiln as indicated by line 33 of Fig, 1;

Fig. 4 is a perspective view of one of the kiln cars; P

Fig. 5 is a partial lan View or 6116 Of the floor slabs of the car;

6 is a partial sectional View through the slab as indicated by sectionline 6--6 of Fig. 5;.

Fig. 7 is a partial plan View showing a similar floor slab provided withround holes instead oi slots;

Fig. 8 is a sectional view taken through the slab as indicated byline8-8 of Fig. 7;

Fig; 9 is a transverse sectional view similar to Fig. 3 but showing amodified construction;

Fig. 10 is also a transverse sectional view similar to Fig. 3 butshowing another modified construction;

Fig; 11 is a perspective view showing a kiln car similar to that of Fig.4 but representing a, further modification;

Fig. 12 is a partial sideelevation showing coupling means connecting theabutting ends of adjacent kiln cars;

Fig, 13 is a partial plan view showing another arrangement of ducts forsupplying heated gases to the preheating section of the kiln; I

Fig. 14 is a partial side elevation of the kiln showing such modifiedduct arrangement; and

Fig. 15 is a partial longitudinal sectional view taken through one ofthe burner ports as indicated by line l5l5 of Fig. 2.

In the embodiment of the invention illustrated in Figs. 1 to 4,inclusive, I show a tunnel kiln 15 having a longitudinal passage ortunnel H3 in which is a track I! for the movement of wheeled cars l8through the tunnel. As will be explained more in detail hereinafter, thecars I8 are designed to carry a quantity of bulk material I9 to betreated or calcined and which may be limestone or any one of variousother materials. As indicated in thedrawings, the bulk material I9 is aloose material in lump form having numerous voids or passages thereinbetween the lumps and through which high temperature combustion gases,or cooling gases as the case may be, can pass as hereinafter explained.As shown in Figs. 1 and 2, a number of the kiln cars 18 is provided andthey extend through the kiln in a series in abutting end-to-end relationwith each other.

By pushing'the cars in succession past a loading station or hopper 20and into the kiln, a more or less continuous movement of the bulkmaterial through the kiln may be. obtained. The .cars emerging from theopposite end of the kiln move past an unloading station having a hopper2| into which the treated material is discharged or dumped to be carriedto a desired point by the conveyor 22. H

The kiln 15 may be constructed with longitudi nal side walls 23 and anarched roof 24 which define or enclose the longitudinal passage ortunnel 16. The side walls 23 and the track I1 may As shown in'Figs. 1and 2. the kiln l5 includes a burni g section 26 in which t e mainportion of the burning or calcining of the bulk material I I9 takes ace,and may also include a preheating section 21 in advance of the burningsection and in w ich some of the heated gases are'uti iaed for prehating the bulk material. A number of burners are rovided at l nitudinall s aced ints in the side w lls of the burnin section 26 for sulyin t e h at used in treatin the bulk material. These burners ma bearran ed to extend through suitable burner blocks 0. locat d in theouter ends of the burner nnrts or o nin s 9. Oil or ot su table u ma bnmflipa 1-, t burners 7R hV the nines 2R1), The 'nr 'heating genti 1 ofth ki n is a so nviribrl with lnnrrifinriin lly s aced orts or openings3" in the side wan; 23. The o ts 3" occupy a l cation s ilartn theburner por s 99 an as wi l he ex lained more fullv h r ina ter, serve asas inl t p ts for the reintro c ion of the he ted ases which are used inreh ating t e material I!! I" The kfln ars l8 are sub tantiall identicalin constructi n. and. as hast shown in Fi s, 3 and 4. ma co ri e a oua rgu ar truck or frame 3| havin flan e su ort wheels 32 arran ed to run ont e rai s I1. The upper portion of the truck or f ame 3| is in the formof an imnerfo ate slah or at orm am on which is constructed a car bnrlv33 adapted to carry the bulk material IS. The bo y 33 may be constructedof heat conductin refractorv material in the form of bricks or slabs aran ed to define a bin or container 34 for the bulk material IS with aspace 35 between Such bin and the platform 3| a for receiving the flamesand heated gases from the burners 2-8. In constructing the car body 33one or more layers 36 of heat insulating refractory bri k may be laid onthe platform 31a and a suitab e number of piers 31 may then be erectedto su port refractory slabs 38 which form the floor of the bin 34. Thebody 33 may also include upright longitudinal side walls 39 formed bylaying refractory brick or the like along the edges of the outermostfloor slabs 38.

As already indicated-above and as shown in drawings an important featureof my invention consists in providing for the passage of hot gasesthrough the bulk material |9, preferably combustion gases of asufficiently high temperature for calcining the bulk material. This isaccomplished by confining the relatively high temperature combustiongases obtained from the burners 28 so that these gases must pass throughthe bulk material in order to reach the free space in the upper part ofthe kiln. To this end I construct the kiln cars l8 so that the gasreceiving or combustion space 35 thereof will be substantially oppositethe burner ports 29, and I also provide numerous openings 40 in thefloor of the bin or container 34 through which the heated gases may passfrom the space 35 upwardly into the bulk material I9. I have found thatby causing the heated gases to pass through the bulk material in thismanner the burning of limestone to produce lime or the calcining ofother materials will be accomplished more eificiently and satisfactorilythan if the heated gases were merely passed over the surface of thematerial.

The openings in the floor of the bin 34 may be either in the form ofspaced slots 43a, as shown in Figs. 5 and 6, or in the form of roundholes 401), as shown in Figs. 7 and 8. To prevent these slots or holesfrom becoming clogged with pieces of the bulk ma-terial being treated Igive the slots or holes a shape such that they will be selfclearing. Inthis instance I obtain this result by tapering the slots or holes 50that they are of downwardly increasing width which permits any pieceswhich enter the slots or holes to drop freely therefrom.

. -In addition to the openings 49 extending 1 through the floor slabs38, I may provide rows of longitudinally extending ports or passages 4|which. also admit heated gases from the space 35 into the bulk material.The passages 4| may be obtained by constructing the piers 31 of varyingheights and arranging the rows of slabs 38 in tiered or steppedrelation, as shown in Figs. 3 and 4. With this arrangement for the floorslabs 38, it will be seen that the center row of slabs forms arelatively elevated floor section 38a and that the intermediate rows offloor slabs, that is the rows on opposite sides of the center row, alsoform relatively elevated floor sections 38b which are of somewhat lesserheight than the section 38a. With the slabs arranged in this steppedrelation, the edges of the slabs of the center row overlap the ,slabs ofthe intermediate rows and the slabs of the intermediate rows overlap theslabs of the outer rows, but in each case the overlapping slab portionsare separated by blocks 4| a which are spaced apart longitudinally ofthe car body to leave the passages 4| therebetween.

In order to confine the high temperature combustion gases obtained fromthe burners 28 so that they must pass through the bulk material, Iprovide longitudinally extending heat seals or gas seals 42 and 43between the cars and kiln at points above and below the burner ports 29.The upper heat seal 42 may be formed by extending a portion of the wall39 of the car body laterally to form a longitudinal flange 44 whichextends into a longitudinal groove 45 formed in the side wall of thekiln. This upper seal may be located adjacent the level of the floor ofthe bin 34 or somewhat above the floor level, as shown in Fig. 3. Thelower heat seal 43 may be formed by extending the longitudinal side edge46 of the truck platform 3| a so as to extend into a longitudinal groove41 of the side wall of the kiln.

These longitudinally extending heat seals 42 and 43, being locatedrespectively above and below the burner ports 29 and the openings intothe space 35 of the car body, will serve to restrict the heated gasesfrom passing upwardly or downwardly between the sides of the car and thekiln walls. By confining the heated gases to the space 35, it will beseen that the gases will be made to pass upwardly into the bulk materialthrough the openings 40 andthe passages 4|. Although I have describedthe floor of the bin 34 as having both the openings 40 and the passagesor ports 4|, it will be understood that either set of openings can beomitted if the other set is found to be sufiicient.

To protect the car wheels and related parts from the heat of the burners28, I may provide the usual longitudinally extending sand seals 48 atopposite sides of the car truck. These seals may comprise longitudinallyextending troughs 48a containing a quantity of sand and depending platesllflbcarried by the trucks and extending downwardly into the sandcontained in the troughs.

It may be desirable to utilize .some of the hot gases which have passedthrough the bulk material id for preheating the material .in advance ofthe burning section 26. For this purpose I may provide more or lessspirally extending ducts 49 which receive heated gases from the upperportion of the burning section 26, preferably at a point adjacent thefirst pair of burners, and carry such gases backwardly and downwardlyal'ongthe kiln for reintroduction into the preheating section 2?. Theducts 49 may be of a length to carry these heated gases a distanceapproximately equal to the length of one car so that the heated gaseswhich have passed through the material carried by one car will bereintroduced into the preheating section 21 at a point to be passedthrough the material of the next adjacent car. The discharge end of theducts 49 may connect with the inlet ports 36, which, as shown in Fig. 3,are located substantially opposite the space 35 of the cars [8. Foracceleratirig'the flow of heated gases through the ducts 49, I mayprovide propeller type fans or blowers B driven from electric motors 5]by shafts 51a. The fans 59 cause the heated gases to be withdrawn fromthe burning section 26 through the ducts M and to be forced through theinlet ports 30 into the Space 35 and then upwardly through the openings49 and ports 4| into the bulk material 19 for preheating the same.

- The preheating of the bulk material as just described may be carriedout in several stages, as represented in Figs. 1 and 2. In this instanceI'show two additional pairs of spirally extending ducts 52 and 53 bywhich the heated gases can be withdrawn from the top of the preheatingsection 21 and reintroduced therein at an earlier point for producingpreheating of the bulk material in the manner already described. A stack54 may be provided adjacent the loading end of the kiln for thedischarge of heated gases which have passed through the preheatingsection 21.

Instead of using the arrangement of spirally extending ducts 89, 52, and53 for reintroducing heated gases into the preheating section 21, I mayuse an arrangement of ducts as shown in the modifiedconstructionillustrat-ed in Figs. 13 and 14. In these'views I Show apreheating section 21a to which heated gases are supplied at a pluralityof points by the piping 55. This piping may include an intake section 56which connects with the upper portion of the burning section 25a and suplies heated gases therefrom to the blower 51.. This blower forces theheated gases through the main pipe 55a and the branch pipes 551) intothe preheating section 21a through the inlet ports 30 with which thebranch pipes 55b are connected. A stack 58 may be connected with themain pipe section 55a for discharging excess gas to the atmosphere.Dampers 59 located in the branch pipes 551) and in the stack 58 may beadjusted to regulate the amount of heated gases desired to bereintroduced into the preheating section 2111.

Certain advantages can be obtained in the operation of my improved kilnby withdrawing heated gases from the upper portion of the burningsection 26 and reintroducing the same through the burner ports 29. Whenthe bulk material being treated is limestone, these gases will consist'largely of carbon dioxide, and the reintroduction of the same throughthe burner ports tends to produce a longer flame at the burners. Whenlonger flames are obtained, they extend farther into the space 35 andeven into the bulk material l9 and thus cause the heat to be appliedmore efiectively to the material. For withdrawing such gases from thetop of the burning section and reintroducing the same through the burnerports, I may provide a blower 60 having intake connections 6| at spacedpoints in the top of the burning section 26 and connection 62 fordischarging such gases into a main duct 53 having branches 64 leading tothe burner ports 29.

The kiln l5 may also include a cooling section I00 through which thecars 18 pass after traversing the burning section 26 and before theyarrive at the unloading hopper 2|. This cooling section is provided with"a plurality of spaced cold air inlet ports iili which correspondsubstantially in location with the burner ports 29 and the inlet ports35 of the preheating section. That is to say, the cooling ports iill arelocated substantially opposite the space 35 of the cars so that cool airwill be directed into this space and can be made to pass through thematerial being treated.

For causing a flow of cool atmospheric air into the kiln through theports I91 I may provide a blower H32 which has an intake connection I03communicating with the upper portion of the cooling section of the kiln.The blower I02 draws cool air in through the ports 10! and causes suchair to pass through the openings 40 and M in the floor of the car intothe bulk material Hi. The air passing through the bulk material coolsthe same and is itself heated during such passage. This heated air canbe discharged to atmosphere by the blower l 132 or preferably, as shownin Figs. 1 and 2, can be discharged into a duct 34 having branches IE5extending along the burning section of the kiln and provided withconnections or nozzles l05a for directing the heated air into the burnerports 29 and secondary air. During this cooling operation the seals 42and :3 between the cars and kiln, and particularly the upper seals 43,restrict the flow of the cool air so that it must pass through thematerial before it can reach the blower I02.

As I have stated above in a general way, the cars I8 extend in a seriesthrough the tunnel of the kiln with the ends of adjacent cars in abuttin.relation. The bodies of the cars are const'ruct'ed so that the bins 34thereof are without end walls, as shown in Fig. 4, and when the ends ofthe cars are in abutting relation, the cars form a substantiallycontinuous support upon which the bulk material is carried as a more orless continuous pile. It will therefore be seen that if the ends of thecars were permitted to separate from each other by even a smalldistance, such as might result from the passage of the cars over irreular portions of the track [1, some of the material would drop into thespace between the adjacent car ends and might result in displacement orother damage to portions of the refractory materials forming the carbody. This difliculty can be avoided by substantially preventing suchseparation between the car ends, and for this purpose I provide couplingmeans on opposite sides of the cars and adiacent the ends thereof which,when connected. will span the joint formed by the car ends and will holdsuch ends in abutting relation. Any suitable form ofcoupling means maybe employed, such as the chains 65 and 66 shown in Fig. 12. A hook 61 ofthe toggle or pelican type carried by the chain 65 may be used toconnect this chain with the chain 66. A spring 68 suitably incorporatedin the chain 66 acts to continuously draw the car ends toward each otherbut is adapted to yield somewhat to afford enough flexibility to preventbreakage.

In Fig. 9 I show a modified form of kiln in which the car Ill differsfrom the car l8 in that the body H is constructed with the floor slabsI2 lying in substantially the same horizontal plane so that the bin 13has a substantially flat floor or bottom. The car body may be providedalong the center line thereof with a relatively elevated section 14forming a longitudinally extending hollow partition or chimney havingtherein a chamber or passage 15, the lower end of which is incommunication with the space 16 beneath the floor of the bin. Theelevated section 14 may be formed of refractory material such as bricklaid up in the form of checker-work so as to provide a number of portsor openings 11 for the passage of heated gases (or cooling air) into thebulk material 18. The relatively elevated section 14 may be constructedso that the walls thereof converge upwardly to thereby obtain a desireddistribution of the heated gases through the ports 11 in relation to thelength of the path which the gases are required to travel through thebulk material. In addition to the ports ll of the relatively elevatedsection 14, I may also provide openings 40 through the floor slabs 12for directing heated gases (or cooling air) upwardly through the bulkmaterial from the space 16. In other respects the car and kilncorrespond substantially with the construction illustrated in Fig. 3 anddescribed in detail above.

In Fig. I show another modification in which the kiln car 8| representsa combination of features contained in the car l8 and in the car 10. Thebody of the car BI is constructed with slabs 82 arranged to form agenerally fiat floor for the bin 83 but has a longitudinally extendingrelatively elevated hollow section or partition 84 at the center thereofand relatively elevated sections 85 extending longitudinally on oppositesides of the center section 84 and lower in height than the latter. Thecenter section 84 is preferably not as high as the section 14 shown inFig. 9, and the top thereof may be formed by a longitudinal row of slabs88 over which the bulk material 81 extends. The side walls of theelevated sections 84 and 85 may have ports or openings 88 therein forthe passage of heated gases (or COOIiIlg air) from the space 89 into thebulk material 81. In addition to the ports or passages 88 I may provideopenings in the floor slabs 82 and in the slabs forming the tops of theelevated sections 84 and 85 for directing heated gases (or cooling air)into the bulk material. In other respects the kiln and the kiln carshown in Fig. 10 are similar to the construction illustrated in Fig. 3.

In Fig. 11 I show still another form of kiln car having the same generalshape as the car l8 but in which the floor and side walls of the bin ofthe car body are constructed of metal. In this modified kiln car 9| thebody 92 is constructed with the bottom thereof formed by slabs '93 madeof a suitable metal or heat resisting alloy, These slabs may besupported by piers 94 and may be arranged in the stepped relation abovedescribed for the floor slabs of the kiln car l8. The metal slabs '93have short legs or projections 93a thereon with gas ports or passages93?) between the pairs of legs and leading from the space 95 beneath thefloor of the bin. The sides or the body may be formed by elongatedplates or slabs 98 also made of a suitable metal or heat resisting alloyand which may be suitably connected to the floor slabs 93. If desired,the floor slabs 93 may be provided with a number of openings 40 which,together with the ports 93b, permit the heated gases (or cooling air) topass from the space into the bulk material. Since metal is a goodconductor of heat, it will be readily seen that the use of metal informing the floor and side walls of the bin portion of the body 92 willpermit heat to pass directly to the bulk material by conduction a wellas by being carried into the bulk material by the heated gases.

In the various forms of kiln cars illustrated and described herein, itwill be understood that the number, size, and arrangement of openings orports through the floor slabs and in the relatively elevated sections ofthe car floor will be such that a desired distribution of the heatedgases (or cooling air) will be obtained to all portions of the load ofbulk material. A substantially uniform distribution of the heated gasesto all portions of the load of bulk material is desirable so that theburning or calcining of the material will be carried out withuniformity. It will also be understood that in all of the abovedescribed kiln cars the floor of the car body and the relativelyelevated sections of the floor are of substantially the same length orplan dimension as the slab or platform 3la of the car truck.

From the foregoing description and the accompanying drawings it will nowbe readily understood that I have provided an improved construction fortunnel kilns and kiln cars with which a more satisfactory and eflicienttreatment of limestone or other bulk material can be obtained.

While I have illustrated and described my improved apparatus in more orless detail, it will be understood, of course, that I do not wish to belimited to the particular details and embodiments herein disclosed, butregard my invention as including such changes and modifications as donot constitute a departure from the spirit of the invention and thescope of the appended claims.

Having thus described my invention, I claim:

1. In apparatus of the character described, a kiln having a tunneltherein, a car movable along said tunnel and having a body including afloor and upright walls defining a bin adapted to carry loose bulkmaterial in lump form to be treated, the floor of said body havingopenings therein for the passage of high temperature combustion gasesthrough the bulk material, burners located to deliver such hightemperature combustion gases into the kiln, and means providing sealsextending longitudinally between the car and kiln adjacent the level ofsaid floor for confining said high temperature combustion gases to causethe same to pass through said openings and bulk material.

2. In apparatus of the character described, a kiln having a passagetherethrough, a car movable along said passage and having a bodyincluding a floor and upright walls defining a bin adapted to carryloose bulk material in lump form to be treated, the floor of said bodyhaving openings therein for admitting high temperature combustion gasesto said bulk material from beneath said floor, burners located todeliver such high temperature combustion gases into the kiln at a pointbelow the level of said floor, and means providing seals extendinglongitudinally between said car and kiln adjacent the level of saidfloor for confining said high temperature combustion gases to causethevsame to pass upwardly through said openings and through said bulkmaterial.

3. In calcining apparatus, a kiln having a pas sage therethrough, awheeledcar movable along said passage and having thereon a structureincluding a floor and upright walls defining a bin adapted to carry aload of loose bulk material in lump form to be calcined, burners in saidkiln arranged to direct high temperature combustion gases toward thecar, said car having a space therein beneath said structure forreceiving said high temperature combustion gases from said burners andopenings leading from said space for directing said high temperaturecombustion gases through the bulk materialjand means providing sealsbetween the carand kiln at points above and below said burners forconfining said gases to cause the same to flow through said openings andbulk material.

4.-In calcining apparatus, a tunnel kiln having a longitudinal passageand burners in its side walls, a series of cars substantially inabutting end-to-end relation in said passage and providing asubstantially continuous support for a load of loose bulk material inlump form to be calcined and including upright walls extending abovesaid support for retaining thebulk material thereon, each of said carshaving a space therein beneath said support for receiving thehigh'temperature combustion gases from said burners and openings leadingfrom said space for directing said high temperature combustion gasesthrough said bulk material, and means providing seals extendinglongitudinally between the cars and kiln at points above and below saidburners.

5. In apparatus of the character described, a tunnel kiln having alongitudinal passage there-- in, a track in said tunnel, acar-comprising a truck having wheels operable on said trackand animperforate slab supported by said truck, a body including a floor andupright walls defining a bin adapted to carry loose bulk material inlump form to be treated, said body being mounted on the truck with aspace between said floor and slab and said floor having openings for thepassage of high temperature combustion gases from said space into thebulk material, and burners in the side walls of the kiln arranged'todirect such high temperature combustion gases into said space. V l

'6. In apparatus of the character described, a tunnel kiln having alongitudinal passage there in, a track in said tunnel, a car comprisinga truck having wheels operable on said track and an imperforate slabsupported by said truck, a body including a floor and upright wallsdefining a 'bin adapted to carry loose bulk material in lump form to betreated, said body being mounted on the truck with a space between saidfloor and slab and said floor having openings for" the passage of hightemperature combustion gases from said space into the bulk material,burners in the side walls of the kiln arranged to direct such hightemperature combustion gases into said space, and means providing sealsextending longitudinally between the car and kiln at points above andbelow said space.

'7. In calcining apparatus, a truck having an imperforate slab thereon,a body constructed on said slab and including a floor and upright wallsdefining a bin adapted to hold loose bulk material in lump form to becalcined, said body having substantially its entire floor spaced fromsaid slab to permit the passage of high temperature combustion gasestherebetween, said fioor having a relatively elevated section providedwith laterally opening passages for admitting the high temperaturecombustion gases to the bulk material from the space beneath the floor,said passages being of an area to admit a suihcient volume of said hightemperature combustion gases to said bulk material to calcine the same.

8. In calcining apparatus, a truck having an imperforate slab thereon, abody constructed on said slab and including a floor and upright wallsdefining a bin adapted to hold loose bulk material in lump form to becalcined, said body having a floor spaced from the slab to permit thepassage of high temperature combustion gases thereoetween, said bodyhaving an upstanding hollow partition in said bin and substantially c0-extensive with one plan dimension of the body, the chamber in saidhollowpartition being in communication with the space beneath the floorof said body to receive said.- high temperature combustion gasestherefrom and the walls of the partition having openings for directingsaid heated gases into the bulk material, said chamber and openmgs beingof an area to supply a sutfioient volume of said high temperaturecombustion gases to said bulk material to calcine the same.

9. In calcining apparatus, a car having an imperforate slab-thereon, abody constructed on said slab and including a floor and upright wallsdefining a bin adapted to hold loose bulk material in lump form to becalcined, said :body, having substantially its entire noor spaced fromthe sla to permit the passage of high temperature .combustion gasestherebetween, said body having an upstanding hollow partition in saidbin and substantially coextensive with one plan dimension of said floor,said hollow partition having an upwardly converging chamber thereinwhich at its lower end is in communication with the space beneath thefloor of the body to receive said high temperature combustion gasestherefrom and the walls of the partition having openings for directingsaid gases into the bulk material.

1-0. In apparatus of the character described, a tunnel kiln having apassage therethrough', a series of cars movable .along said tunneland'eac'h car having upright walls and a floor defining a bin adapted tocarry loose bulk material in lump form to be treated, the floors of saidoars having openings for directing high temperature combustion gasesthrough said bulk material, refractory means providing seal-s extendinglongitudinally between said cars and kiln, burners in a wall of the kilnfor delivering said high temperature combustion gases thereinto at apoint below said seals, and means for withdrawing from the kiln at apoint above said seals combustion gases which have passed through saidmaterial and reintroducing .said gases into the kiln at a point belowsaid seals.

iii. In apparatus of the character described, a tunnel kiln having aburner section and a preheating sect-ion, burners in a wall of saidburner section, gas inlet ports in a wall 'ofsaid preheating section, aseries of cars in said tunnel each car having a body including a floorand Walls de. fining a bin adapted to support bulk material'to'becalcined, the floors of said cars beingat an =elevation above saidburners and inlet ports and the body of each car having a spacethereinfbeneath its floor adapted to receive high temperature combustiongases from said burners and inletports, said floors having openingstherein leading from said spaces for directlng ;the high temperaturecombustion gases through thebulk material, and ducts connected with theupper portion of said tunnels so as to receivecombustion gases whichhave passed. through the bulk, material and to redeliver the same intothe kiln through the inlet ports of said preheating section.

12. In apparatusof the character described, a tunnel kiln having aburner. section and a preheating section, burners ina wall of. said.burner section, gas inlet ports in a wall of said preheating openingsand throughsaid bulk material, and

means for withdrawing from the kiln at a point above the sealscombustion gases which have passed throughsaid material andreintroducing the same through said ports into the preheating section ofthe kiln below said seals.

13. In apparatus of the character described, a tunnel kiln having aburner section. and a preheating ,section, burners .in the walls of saidburner section, gas inlet ports in the walls of said preheating section,a seriesof cars in said tunnel, each car having a body including a floorand walls defining a bin adapted to support bulk material to becalcined, the body of each car having a space therein, beneathits flooradapted to receive high temperature combustion gases from said burnersand inletports, the floor of each car having openings therein leadingfrom said space for directing the high temperature combustion gasesthrough the bulkmaterial, means providing heat seals betweenthe cars andkiln at points above and below said burners and ports, and means, for,withdrawing from the kiln combustion gaseswhich have passedthrough thebulk materialand forcing the same through said ports into the preheatingsection of the kiln atla point between said seals.. .c r,

14. In apparatusofthe character-described, a kilnhaving a, coolingsection provided with inlet ports for cooling air, a car movable in saidcooling section and havinga body providedwith a floor at a level abovesaid ports, said body having walls defining a bin adapted to carry aloose bulk product to be treated and said floor having openings for thepassage of cooling air in contact with said bulk product, meansproviding seals extending longitudinally between the car and kilnadjacent the level of said floor, and power driven means for withdrawinggaseous medium from the upper portion of the cooling section for inducina flow of cooling air through said inlet ports and through said flooropenings incontact with, said bulkproduct. V V V 15. In apparatus of thecharacter described, a kiln having a burning section and a coolingsection, burners in said burning section, air inlet ports in saidcooling section, a car movable ,in said kiln and having a body providedwitha floor at a level above said burners and ports, sai d body havingwalls defining a bin adapted to carry loose bulk material to be treatedand said floor, having.

openings and said material, and means for delivering at least a portionof the withdrawn gaseous medium to said burners.

16. In apparatusof the character described, a tunnel kiln having alongitudinal passage therein, a track in said passage, a car comprisinga truck having wheels operable on said track and an imperforate slab onsaid truck, a body on said truck including a floor and spaced wallsdefining a bin adapted to carry bulk material to be treated, said carhaving a space between said floor and slab and which extends forsubstantially the full length of the car and is open along at least oneside thereof, and a burner in a wall of the kiln located to direct hightemperature combustion gases into said space substantially continuouslyduring movement of the car past said burner, said floor having openingstherein for directing said high temperature combustion gases from saidspace into the bulk material.

17. In apparatus of the character described, a tunnel kiln having alongitudinal passage therein, a track in said passage, a car comprisinga truck having wheels operable on said track and an imperforate, slab onsaid truck, a body on said truck including a floor and spaced wallsdefining a bin adapted to carry bulk material to be treated, said carhaving a space between said floor and slab and which extends forsubstantially the full length of the car and is open along at least, oneside thereof, means providing seals extending longitudinally between thecar and kiln and located to confine gas in said space, and a burner in awall of the kiln located to direct high tempera- 40 ture combustiongases into said space substantially continuously during movement of thecar past said burner, said floor having openings therein for directingsaid high temperature combustion gases from said space into the bulkmaterial.

18. In apparatus of the character described, a tunnel kiln having alongitudinal passage therein, a track in said passage, a car comprisinga truck having wheels operable on said track and an imperforate slab onsaid truck, a body onsaid truck including a floor and spacedwallsdefining a bin adapted to carry bulk material to be treated, saidcar having a space between said floor and slab and which extends forsubstantially the full length; of the car and is open along the sidesthereof, and burners in ,the side walls of the kiln located to directhigh temperature, combustion gases into saidspace from oppositesidesxthereof substantially continuously during movement, of the carpast said burners, said floor having opene ings therein for directinghigh temperature combustion gases from said; space into the bulkmaterial.

19. In a paratus of the character described, a kiln having a tunneltherein, a series of cars movable along said tunnel and each comprisinga wheeled truck having thereon an imperiorate slab and a body providedwith a floor and spaced walls defining a bin adapted to carry, bulkmaterial to be treated, each car having a space between its floor andslab and which extends for substantially the full length of thecar andis open along the sides thereof, said 'carshaving their endssubstantially in abutting relation so that saidfloors provide asubstantially continuous support for said material with a substantiallycontinuous space between such support and said slabs, and burners in theside walls of the kiln located to direct high temperature combustiongases into said space fromopposite sides thereof substantiallycontinuously during movement of the cars along the tunnel, said floorshaving openings therein for directing said high temperature combustiongases from said space into the bulk material.

20. In apparatus of the character described, a kiln having a passagetherein, a series of wheeled cars movable along said tunnel and havingbodies thereon adapted to carry bulk material to be treated, said bodiesincluding floors and side walls and having open ends substantially inabuttin relation so that said floors form a combined transversepartition in the kiln and a substantially continuous support for thebulk material, said floors having openings therein permitting thepassage of high temperature combustion gases through the bulk material,burners in the wall of the kiln for delivering such high temperaturecombustion gases thereinto on one side of the bulk material and beneathsaid partition, and means for withdrawing gases from the kiln on theother side of the bulk material and partition for inducing a flow of thegases through said openings and bulk material.

HENRY M. BEAT'I'Y.

